Good morning. Here are the result thus far.
So I went looking. I started with Sabretooth as they make a sensational dual motor driver for my rc paddlesteamer which allows the motors to operate in a tank like fashion. I can spin the ship (1.5 m long) in it's own length. Awesome.
Quick vid of the ship.
Anyway I was so impressed with Sabretooth that I kept the paperwork and went looking for a dual motor driver. Found this
Sabertooth 2X12 Dual Motor Driver - Robot Gear Australia
Dunno if I should post that. Guess I'll find out.
Anyway, cost by two is an issue.
The reason for all this was to discover and prove to myself that I could drive multiple motors with an Arduino. That has been proved.
I have also proved that I can drive steppers with an Arduino.
Now I need to consult with yourselves, and a couple of others, before deciding the next steps.
This whole process has been an immense challenge but intensely rewarding. Your help has been invaluable. Thank you.